1. The problem statement, all variables and given/known data A ray of light is incident in water on a plane water-glass boundary. The angle of incidence is 30 degrees. Calculate the angle of refraction. (Refractive index of glass with respect to air =3/2, refractive index of water with respect to air = 4/3). 2. Relevant equations n1sini = n2sinr 3. The attempt at a solution I tried approaching it with several methods, but I am puzzled. How do you get the glass to water refractive index from the data given?? Any help would be greatly appreciated. Thank you!